replace instruction. Figure 8-1 illustrates instructions
with their classification (read (R), store (S), or replace
(RP)).
Read —Read instructions acquire an operand
from main memory.
Store —Store instructions process an operand
already acquired and store it in main memory.
Replace —Replace instructions acquire and
process an operand and then store it in memory.
INSTRUCTION LANGUAGE
INTERPRETATION
The instruction format provides the means to
customize each instruction. A list of instructions with
their formats, symbols, and meanings provides you a
means to interpret what an instruction will ultimately
accomplish. This is a very useful troubleshooting
tool to help isolate a specific malfunction. The in-
structions differ between types of computers. Take a
Figure 8-1.—Examples of computer instructions.
8-5
